See also Enhanced Interior Gateway Routing Protocol (EIGRP).

A More Efficient Distance Vector Routing Algorithm (PDF)
A whitepaper by J. J. Garcia-Luna-Aceves.

Advanced Encryption Standard (AES)
This document describes the Advanced Encryption Standard feature in Cisco IOS Release 12.2(13)T.

Enhanced Interior Gateway Routing Protocol (EIGRP)
EIGRP contains several important protocols that greatly increase its operational efficiency relative to other routing protocols. One of these protocols is the Diffusing update algorithm (DUAL) developed at SRI International by Dr. J.J. Garcia-Luna-Aceves. DUAL enables EIGRP routers to determine whether a path advertised by a neighbor is looped or loop-free, and allows a router running EIGRP to find alternate paths without waiting on updates from other routers.